1. Field of the Invention
This invention relates to air lumbar support devices in general, and more particularly to an air lumbar support device of the type utilized in an automobile seat.
2. Prior Art of the Invention
It is well known in the art to provide the seat back of an automobile seat with a plurality of horizontally disposed parallel air bags so that the curvature of the seat back can be adjusted selectively by regulating the air pressure within the individual air bag. Referring to FIG. 1 showing a conventional air lumbar support device, each air bag 11 of a seat back 10 is uniformly provided with pressurized air supplied from an electric-powered air pump 12. The air pressure of each air bag 11 is controlled by an air control valve 13 so that the lumbar portion of the driver may fit the seat back 10 in the most suitable state. More particularly, through means of the air control valve 13 the pressurized air is supplied from the air pump 12 to each air bag 11 to thereby cause the air bag to inflate.
The internal air pressure of each air bag 11 can be held by the check valve (not shown) accommodated in the air control valve 13. Under these conditions, the check valve is brought in its opened portion when the switch knob (not shown) of each air bag 11 is pushed, and during pushing the switch knob the check valve can be maintained in its opened position. Subsequently, the pressurized air will be released from each air bag 11 respectively so that the curvature of the seat bag 10 may be adjusted into the suitable form.
In the above-mentioned conventional air lumbar support device, however, each time the driver is relieved, it will be necessary to re-adjust the air pressures of the seat bags into the suitable state for the driver or into the state which the driver desires. Since the air pressures should be adjusted manually, the performance of the operation is inferior and then it takes much time to complete the adjustment of the air pressures. Moreover, the manual adjustment must be usually completed during stopping the automobile, namely the manual adjustment can not be easily completed during driving the automobile.